The superintendent of a school district wanted to predict the percentage of students passing a sixth-grade proficiency test. she obtained the data on percentage of students passing the proficiency test (% passing), mean teacher salary in thousands of dollars (salaries), and instructional spending per pupil in thousands of dollars (spending) of 47 schools in the state. following is the multiple regression output with y = % passing as the dependent variable, x1 = salaries and x2 = spending: which of the following is the correct null hypothesis to determine whether there is a significant relationship between percentage of students passing the proficiency test and the entire set of explanatory variables? a) h1: =b3=0

b) h1: =b1=0

c) h1: =b2=0

d) h1: =b0=0